Input/output (I/O) plays a crucial role in computer and telecommunication. High-speed serial communication may offer greater advantages than parallel communication. In terms of distance, the cost of cable and synchronization requirements makes serial communication a practical choice. In terms of speed, parallel communication may no longer provide a reliable, cost effective means to keep signals synchronized once data rate exceeds about 1 Gb/s.
However, serial I/O based designs have their own performance limitations as signal processing became more sophisticated. Pad capacitance may be a key limitation for high-speed serial I/O performance. Cpad may reduce rise/fall edge rate at the receiving end introduce insertion loss and termination mismatch, and produce Inter-Symbol Interference (ISI) jitter.